A speed assistant is configured to keep the speed of a motor vehicle at a predetermined value. As a result, the driver of the motor vehicle may be relieved of the task of the longitudinal control of the motor vehicle. In one variant, a distance from a preceding vehicle is also determined, and the speed of the motor vehicle is controlled in such a way that a predetermined minimum distance from the preceding vehicle is maintained. For this purpose, the predetermined speed may be undershot. The determination of the distance from the preceding vehicle takes place, for example, with the aid of a radar sensor or video sensor.
In certain situations, returning control of the longitudinal speed of the motor vehicle to the driver is necessary. For example, if the motor vehicle is following another vehicle and a third vehicle is cutting in between these two vehicles, the minimum distance to be maintained from the preceding vehicle may be abruptly undershot. In this case, a deceleration of the motor vehicle may be necessary which exceeds a predetermined threshold value, above which a braking operation may not be perceived as comfortable. In this case, the driver may be prompted to take over the speed control.
German Published Patent Appln. No. 10 2004 005 229 describes a distance control system for motor vehicles.
A corresponding warning or prompt may occur suddenly, so that the driver may be unable to respond appropriately in order to cope with the present traffic situation. The object of the present invention is therefore to provide a technique with which an improved transfer of a speed control of a motor vehicle to the driver may be carried out. The present invention achieves this object with the aid of the subject matter of the independent claims. Subclaims specify preferred specific embodiments.